Grumman AA1A 150hp Performance

cfd408

cfd408

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Peter
I found a Grumman AA1A with a STC for 150hp that I'm interested in buying. Wondering what performance improvements I might expect over the original 100hp. I've heard improved climb and a few knots cruise. Any improvement to useful load or service ceiling.
I live in Colorado.. my home field is 5800' and with summer heat and lack of humidity that can easily jump to over 9000'.
Any info you can provide is greatly appreciated.
Yes, I know a 180hp 172 or PA28 would be a better choice.. just interested in info for the AA1A at the moment.
Thanks!
 
Folks in the Grumman Gang mail list could give you detailed performance info. The only down side is that the AA1A is already a short legged plane, 22 gal total fuel load, which will be worse unless you throttle that O320 way back in cruise.

With the stock engine, 6+ GPH, you need to be over an airport at 3 hours. That's the way I flew mine. With the STC engine upgrade climb will be excellent with 50 hp in excess.
 
Though not apples to apples, my 160-bhp RV-9A with an IO-320 burns about 8 gph LOP (at about 155 KTAS) when I really want to get somewhere on a cross country. So you might be looking at legs of just over 2 hours on a longer trip to keep an adequate reserve. A lot depends on your mission and/or tolerance for frequent fuel stops. 1.5 hour round-trip breakfast hops? Perfect. Or just throttle back, as chemgeek suggests.

They look like fun...I was shopping the AA1A before I decided to go the experimental route.
 
A buddy had an 0-290 powered AA1. That STC didn't result in a gross weight increase, so he had a very low useful load for an airplane that burned more gas than a stock version. Do the 0-320 versions get a weight increase?
 
Interesting thought. If they use the same engine and bore bigger holes in the same cylinders to get the increase in hp, then perhaps a weight decrease?
Don't think they are the same engines with bigger pistons, but who knows. Wiki shows 290 at 264 lbs, and 320 at 244 lbs.
Then again, weight difference could be due to better, more lightweight alloys. When the 290 was introduced, Hitler was becoming famous. :^)
I love the Grumman birds.
 
There will be a BIG increase in performance over stock. As mentioned, the useful load on these planes are not very good to begin with especially if you add the auxiliary tanks
 
I imagine that 150 hp STC would come in mighty handy in Colorado. Just a thought.
 
cfd408 said:
I found a Grumman AA1A with a STC for 150hp that I'm interested in buying. Wondering what performance improvements I might expect over the original 100hp. I've heard improved climb and a few knots cruise. Any improvement to useful load or service ceiling.
I live in Colorado.. my home field is 5800' and with summer heat and lack of humidity that can easily jump to over 9000'.
Any info you can provide is greatly appreciated.
Yes, I know a 180hp 172 or PA28 would be a better choice.. just interested in info for the AA1A at the moment.
Thanks!
Click to expand...
Centennial, hm? Have you flown a 160 hp 172 or a warrior to see how you like flying it this week, in this weather?
Also consider maintenance. More difficult to get Grumman parts than Piper or Cessna.

An RV-9 weighs a bit over 1,000#.
The Grumman, about 1500. That 500 pound (50%) difference with the same O-320 engine is HUGE!
The 172M (150 hp) is about 1400 pounds.
The 172P (last one with the O-320 engine but 160 hp) is 2400 pounds. It's really not practical to do an equal comparison.

If you're looking for performance out here in the summer, an RV9 is your best bet. Excellent gas mileage, too. On the other hand, don't expect to take a lot of gear with you. Remember maintenance and insurance. I really like the Grummans, almost bought a AA5 but it got sold 3 hours before I got there (with check in hand).

A number of the EAA guys in my chapter keep telling me I need to build an airplane (an RV or a Glastar). For years, they've been telling me this. But then, come Oshkosh time, they ask if I'm flying there, and can I take their camping gear and such? (They got 30-50 pound load, I got 1000 pound load, or 700 after fuel). All of a sudden my very boring cherokee is very much in demand.
 
FWIW, Useful load in a 172N with 160 HP is 2300#. There's a STC to increase it to 2400# which requires limiting flaps to 30 degrees (instead of 40). The stock airframe can carry the load; it's go-around performance at max flaps that's lacking.
 
murphey said:
Centennial, hm? Have you flown a 160 hp 172 or a warrior to see how you like flying it this week, in this weather?
Also consider maintenance. More difficult to get Grumman parts than Piper or Cessna.

An RV-9 weighs a bit over 1,000#.
The Grumman, about 1500. That 500 pound (50%) difference with the same O-320 engine is HUGE!
The 172M (150 hp) is about 1400 pounds.
The 172P (last one with the O-320 engine but 160 hp) is 2400 pounds. It's really not practical to do an equal comparison.

If you're looking for performance out here in the summer, an RV9 is your best bet. Excellent gas mileage, too. On the other hand, don't expect to take a lot of gear with you. Remember maintenance and insurance. I really like the Grummans, almost bought a AA5 but it got sold 3 hours before I got there (with check in hand).

A number of the EAA guys in my chapter keep telling me I need to build an airplane (an RV or a Glastar). For years, they've been telling me this. But then, come Oshkosh time, they ask if I'm flying there, and can I take their camping gear and such? (They got 30-50 pound load, I got 1000 pound load, or 700 after fuel). All of a sudden my very boring cherokee is very much in demand.
Click to expand...

I haven't seen any RV-9s on the market and confess I don't know much about them. Since it's really just me and the wife and possibly a duffle bag with a change of cloths I'm not looking for really big useful loads. I like the PA28's but not keen on the idea of taking off with two-thirds fuel just to get off the runway on a hot summer day. You make a very valid point comparison wise.
 
steingar said:
I imagine that 150 hp STC would come in mighty handy in Colorado. Just a thought.
Click to expand...

very much! I try not to look at anything with less than 180hp.. but considering the 50% increase in hp and the bird in question is located at a field with an elevation over 7000ft I figured it was worth a look
 
trenton said:
FWIW, Useful load in a 172N with 160 HP is 2300#. There's a STC to increase it to 2400# which requires limiting flaps to 30 degrees (instead of 40). The stock airframe can carry the load; it's go-around performance at max flaps that's lacking.
Click to expand...

That's max gross, not useful. The number is correct for max gross. If you use the Penn Yan STC for 180hp and 30 degrees limitation on the flaps you get a max gross increase to 2550 pounds with very little increase in empty weight. The 172N in the club has this and with full long range tanks (50 gal) I can still put around 755 pounds in the cabin. Beats our 182P by over 100 pounds (again with full long range tanks). Quite a load hauler. Our 172P has the 2400 pound max gross as its flaps are limited to 30 degrees. That 100 pounds extra in the cabin be quite useful, but I still prefer the 172N with 180 hp as I don't even have to think about W&B with just my wife and me aboard. And it climbs like a homesick angel compared with 160 hp.
 
cfd408 said:
I haven't seen any RV-9s on the market and confess I don't know much about them. Since it's really just me and the wife and possibly a duffle bag with a change of cloths I'm not looking for really big useful loads. I like the PA28's but not keen on the idea of taking off with two-thirds fuel just to get off the runway on a hot summer day. You make a very valid point comparison wise.
Click to expand...
Go to EAA chapter meetings. Lots of RVs. Head over to Van's website and see who's selling. Come to a Young Eagles rallye and chat with owners, might even get a ride. PM me and I'll send more info.
 
murphey said:
Also consider maintenance. More difficult to get Grumman parts than Piper or Cessna.
Click to expand...

From your post, you say you "almost" owned one. I've owned one for 12 years. I've never found a single Grumman specific part that required more than two phone calls to find. Generally significantly less expensive than Piper/Cessna as well. About the only things in short supply are center spars for the Tiger, and the shock absorbers used on the nose landing gear of the '78 and later Tigers. Cheetah and two-place spars are common, and luckily the shocks are listed as "optional" equipment and can be removed.

murphey said:
An RV-9 weighs a bit over 1,000#.
The Grumman, about 1500. That 500 pound (50%) difference with the same O-320 engine is HUGE!
Click to expand...

OP was specifically asking about a 150 HP AA1A. The two seater, not the four-seat Cheetah/Traveller/Tiger. Standard empty weight for an AA1A is 1,018 lb, with the O-235-C2C installed. Upgrading to the O-320-E2G adds an extra 24 pounds, for an empty weight of 1042lbs.

Van's quotes an empty weight of 1015 - 1057 lbs for the RV9/9A.
 
Comparing the RV9 to a Grumman AA1 is apples and oranges. You could get a nicely equipped Tiger for what you'd pay for an RV9, unless you built it yourself. Actually, you'd pay just as much and have to build the fool thing.
 
steingar said:
Comparing the RV9 to a Grumman AA1 is apples and oranges. You could get a nicely equipped Tiger for what you'd pay for an RV9, unless you built it yourself. Actually, you'd pay just as much and have to build the fool thing.
Click to expand...

Yes, but then you'd have built an airplane...in your garage! And have a shiny, zero-time airframe, be able to do your own annuals, etc.

Mine carries 100 lb. of baggage quite easily, plus full fuel, and a couple of 200-plus-pound guys.
 
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